DESCRIPTION: The overall objective of this research project is to investigate the effects of EMF exposure on proliferation of astrocytoma cells and assess the role of protein kinase C (PKC) in such effect. Epidemiological studies suggest EMF is associated with an increased incidence of brain tumors, and in particular astrocytomas. Studies on the biological effects of EMF at the cellular level suggest that EMF may act as a tumor promoter. Therefore, this proposal is structured to test the hypothesis that in astrocytoma cells the effect of EMF alone or in combination with known mitogens involves activation of PKC. Three aims are proposed to pursue this hypothesis. The first is to investigate the effect of EMF on the proliferation of human astrocytoma cells alone or in combination with a number of mitogens. The second aim will compare the effects of EMF on astrocytoma cells with those on non-transformed astrocytes and other cell lines derived from different tumors. The final aim will investigate whether PKC is involved in the observed mitogenic effect of EMF.